Quick replacement mechanism for mounting dies in press

ABSTRACT

For mounting a die set in a press, with the press open a pair of apertured anchor bars are secured in parallel, spaced relation to the press platen, and a pair of similar bars are secured to the press ram. A die set, consisting of at least an upper die and a lower die, is placed on the platen between the anchor bars, each die of the set having a flange extending from each end thereof. A pair of hold-down rods, each having round end portions and an eccentric intermediate portion, are inserted through axially opposite pairs of holes in the anchor bars, one over each end flange of the lower die. The hold-down rods are rotated so that their eccentric, intermediate portions bear on the die flanges and thus clamp the die into securely locked position on the press platen. The press is then shut, and the upper die is similarly secured to the ram. Thereafter the press is operated in a usual manner until it is time to remove the dies, when the foregoing procedure is reversed.

United States'Patent Weidel Rohr Industries, Inc., Chula Vista, Calif.

Filed: May 5,1971 Appl. No.: 140,535

Inventor:

Assignee:

US. Cl '....72/48l, IOU/DIG. 18, 248/25 Int. Cl... .L ..B2ld 37/04, Fl6f 15/00 Field of Search ..72/48l; 248/25, 361 B;

IOO/DIG. 18

References Cited V UNITED STATES -PATENTS 2,222,597 11/1940 'Solger ..72/48l Primary Examiner-Charles W. Lanham Assistant Examiner-R. M. Rogers Att0rney--George E. Pearson 1 Nov. 14, 1972 ABSTRACT For mounting a die set in a press, with the press open a pair of apertured anchor bars are secured in parallel, spaced relation to the press platen, and a pair of similar bars are secured to the press ram. A die set, consisting of at least an upper die and a lower die, is placed on therplaten between the anchor bars each die of the set having a flange extending from each end thereof. A pair of hold-down'rods, each having round end portions and an eccentric intennediate portion, are inserted through axially opposite pairs of holes in the anchor bars, one over each end flange 'of the lower die. The hold-down rods are rotated so that their eccentric, intermediate portions bear on the die flanges and us clamp the die into securely locked position on the press platen. The press is then shut, and the upper die is similarly secured to the ram. Thereafter the press is operated in a usual manner until it is time to remove the dies, when the foregoing procedure is reversed.

4 Clains, 3 Drawing Figures PATENTEDuuv 14 I912 3,702,560

IIHII' I I INVENTOR. FIG. '1 1 JOSEPH c. WEIDEL ATTORNEY QUICK REPLACEMENT MECHANISM FOR MOUNTING DIES IN PRESS BACKGROUND OF INVENTION In the forming and drawing of sheet metal it is necessary at times to heat the dies, for example, in the case of a deep or difficult draw, or when working certain metals such as titanium. When using hot dies it is important to get them mounted quickly before they cool off, and when using conventional means, such mounting is a hot, difficult, dangerous job, particularly since the platen and ram are also hot. While some attempts have been made in the past to provide quick change die mounting means, so far as is known no entirely satisfactory means have previously been available for this purpose.

PURPOSE OF THE INVENTION A primary objective of the present invention is to provide a quick, simple, positive, and easily interchangeable die mounting mechanism. More specifically, the invention provides a pair of apertured anchor bars for mounting on each, the platen and ram of a press, each pair of anchor bars spaced apart to receive a die set therebetween, each die of such die set having an endwise extending flange on each end thereof, and a pair of eccentric hold-down rods for each die. Each hold-down rod is inserted through a pair vof aligned holes in a pair of the anchor bars, on hold-down rod overlying each die end flange, and rotated into eccentric, bearing, clamping relation with its respective end flange thereby securely clamping the dies to the press platen. and ram, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing objectives and advantages of the invention will be apparent from the following description and the accompanying drawings, wherein:

FIG. 1 is a fragmentary, perspective view showing portions of the platen and ram of a hot forming press with the lower and upper dies of a die set clamped respectively thereto.

FIG. 2 is an enlarged, fragmentary, sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is a perspective view of one of the eccentric hold-down rods, an intermediate portion being broken away,

DETAILED DESCRIPTION OF THE DRAWINGS Referring to the drawings in detail, the platen or bed 10 and ram 11 of a conventional press, not otherwise shown, such as a mechanical or hydraulic punch or draw press, have a plurality of threaded holes 12 in each thereof for threadedly receiving screws, such as conventional die screws 13. The screw holes 12 are arranged in rows, the rows spaced apart transversely of their length, and the holes in each row spaced apart to receive the screws 13 to secure a pair of anchor bars 14 and 15 on the platen 10 in parallel, selected, laterally spaced relation.

The anchor bars are notched at 17, see FIG. 2, at the upper end of each screw hole so that the heads of the screws 13 do not project above the tops of the anchor bars. Each anchor bar has also a row of holes 18 transversely therethrough, the holes 18 being spaced apart by selected short distances. The anchor bars 14 and 15 are secured to the platen by the screws 13 with the transverse holes 18 in each anchor bar 14 and axially aligned with those in the other anchor bar.

A similar pair of anchor bars 19 and 20 are similarly mounted on the ram 11, directly above the anchor bars 14 and 15, respectively the press being open, and preferably unheated, during the mounting of the anchor bars.

It is necessary that each die to be secured to the platen or ram of a press in accordance with the present invention have a pair of end flanges 21 of uniform, known thickness thereon, one such flange extending 5 from each end of each die and flush with the bottom of the die. The term bottom as used herein is intended to mean the surface which seats to the press platen or ram, as the case may be.

In the drawings, a simple, two die, forming die set 22 is illustrated, but it is obvious that the invention can be used with more complicated and sophisticated die sets, including drawing and punching dies, etc. The illustrative die set 22 comprises an upper die 22a and interfitted lower die 22b. The upper die 22a is shown in solid lines in FIG. 1 as it appears with the press open, and in broken lines in the same figure as it appears with the press shut.

A plurality of four similar hold-down rods 23 are provided, each hold-down rod having round end portions 23a and 23b, which are axially aligned, and an integral, enlarged, eccentric, intermediate portion 230. A squared end portion 24 is provided on each hold-down rod to fit into the socket of a conventional socket wrench 25 for rotating the rods into clamping, flange engaging position.

The transverse holes 18 in the anchor bars 14 and 15 are of a size to receive the eccentric portion 23c of a hold-down rod 23 freely therein, and these holes preferably are elongated somewhat lengthwise of the anchor bar in which they are located, as best shown in FIG. 2, to allow a slight adjustment of the hold-down rod preparatory or during clamping. The outer surface defining each of the transverse holes 18 in the anchor bars is spaced from the bottom of its respective anchor bar by a distance slightly less than the distance, measured diametrically of a hold-down rod, from the high point of the eccentric portion 230 of such hold-down rod to a straight line along the round end portions 23a and 23b on the diametrically opposite side of such rod, plus the known uniform thickness, of the flanges 21. Thus, when a hold-down rod 23 is inserted in an axially aligned pair of holes 18 in the anchor bars 14 and 15 over a die flange 21 as shown in FIGS. 1 and 2, and is turned rotatively about its axis to force the eccentric, intermediate rod portion 23c downwardly onto such flange 21, such action clamps the flange securely to the platen 10, but the eccentric portion 230 is not allowed to swing through.

OPERATION In using the invention, a pair of anchor bars 14 and 15 are secured by the screws 13 to a press platen 10 in parallel, spaced apart relation, with the transverse holes 18 in each of such anchor bars axially opposite those in the other. The anchor bars 14 and 15 are spaced apart to receive the round end portions 23a and 23b of a hold-down rod 23, one in each of a pair of the axially aligned holes 18 in the anchor bars 14 and 15. A second pair of anchor bars 19 and 20 are similarly secured to the ram 11 directly above the anchor bars 14 and 15, respectively.

With the press upon which the anchor bars 14, 15, 19 and 20 are thus mounted open, a die set 22, comprising at least a lower die 22a and associated upper die 22b, is placed on the press platen between the anchor bars 14 and substantially as shown in combined solid and broken lines in FIG. 1, with the die flanges 21 extending endwise relative to the direction of the anchor bars secured to the platen.

A hold-down rod 23 is then inserted through axially opposite pairs of holes 18 in the anchor bars 14 and 15 to overlie each end flange 21 of the lower die 22b, and to position the round parts 23a and 23b of such holddown rods within the holes 18 in the anchor bars in which they are inserted. By means of a suitable wrench 25, or other power multiplying means, each of the holddown rods thus inserted is then turned rotatively about its axis to force its eccentric, intermediate portion 23c down into clamping relation with the die flange 21 therebeneath, thereby securely locking the lower die 22b to the platen 10.

The press upon which the dies are being mounted is then shut, bringing the ram 1 1 down onto the upper die 23a, and the upper die is then secured to the ram 11 in a manner similar to that described for the lower die 22b. The press is then ready to use in a conventional manner until it is desired to remove the dies, whereupon the foregoing procedure described for mounting the dies is reversed.

The invention provides a simple, quick, safe and positive mechanism for mounting dies in a press, and is particularly useful when using hot dies.

Having thus described my invention, what I claim as new and useful and desire to protect by U. S. Letters Patent is:

1. For releasably mounting a selected die set having a lower die and interfitted upper die in a press having a platen and a ram, die clamping mechanism comprising:

a substantially integral flange extending endwise from each end of each of the dies, the flanges being of equal, known thickness, and flush with the bottom face of their respective dies,

a pair of anchor bars releasably secured in parallel, laterally spaced relation to the platen of such press on opposite sides of such lower die, each anchor bar having an aligned row of holes transversely therethrough, the upper edges of such transverse holes being parallel, and uniformly spaced from the bottoms of their respective anchor bars,

pair of hold down rods, each thereof inserted through laterally opposite holes in the two anchor bars, and extending transversely therebetween, one of the hold down rods overlying each end flange of such lower die positioned on the press platen between the anchor bars, each of the hold down rods being of a width, measured diametrically from the high point of the eccentric portion thereof to a line defined by the opposite sides of the end portions, slightly greater than the distance from the bottom of each anchor bar to the tops of the transverse holes therein, each hold down rod being turned rotatively about its axis, after insertion in such holes, to force the eccentric portion of such hold down rod into clamping engagement with the die flange over which it is positioned, and

a second, similar pair of anchor bars and hold down rods similarly secured and positioned with respect to the press ram, the second pair of hold down rods being in similar clamping engagement with the end flanges of the upper die of such die set.

2. Die clamping mechanism as claimed in claim 1 wherein the platen and ram of a press upon which the die set is to be mounted are each provided with a plurality of rows of threaded holes therein, each of the anchor bars is positioned to overlie a row of the holes and is provided with a plurality of holes therethrough located to register with selected ones of the threaded holes over which said each anchor bar is positioned, and a plurality of screws inserted one in each of a selected plurality of such holes in said each anchor bar and screwed into the threaded hole in register therewith, each of said screws being drawn down tight to secure the anchor bars firmly in position.

3. Die clamping mechanism as claimed in claim 1 wherein each of the holes transversely through each of the anchor bars is elongated lengthwise of its respective anchor bar to provide limited adjustment of a hold down rod inserted in such hole.

4. Die clamping means as claimed in claim 1 wherein an end portion of each hold down rod has a non-circular end portion formed thereon, and a socket wrench has a non-circular socket therein shaped to receive the non-circular end portion of the hold down rod in closely interfitted relation therein for turning each hold down rod about its axis into clamping relation with a die end flange therebeneath. 

1. For releasably mounting a selected die set having a lower die and interfitted upper die in a press having a platen and a ram, die clamping mechanism comprising: a substantially integral flange extending endwise from each end of each of the dies, the flanges being of equal, known thickness, and flush with the bottom face of their respective dies, a pair of anchor bars releasably secured in parallel, laterally spaced relation to the platen of such press on opposite sides of such lower die, each anchor bar having an aligned row of holes transversely therethrough, the upper edges of such transverse holes being parallel, and uniformly spaced from the bottoms of their respective anchor bars, a pair of hold down rods, each thereof inserted through laterally opposite holes in the two anchor bars, and extending transversely therebetween, one of the hold down rods overlying each end flange of such lower die positioned on the press platen between the anchor bars, each of the hold down rods being of a width, measured diametrically from the high point of the eccentric portion thereof to a line defined by the opposite sides of the end portions, slightly greater than the distance from the bottom of each anchor bar to the tops of the transverse holes therein, each hold down rod being turned rotatively about its axis, after insertion in such holes, to force the eccentric portion of such hold down rod into clamping engagement with the die flange over which it is positioned, and a second, similar pair of anchor bars and hold down rods similarly secured and positioned with respect to the press ram, the second pair of hold down rods being in similar clamping engagement with the end flanges of the upper die of such die set.
 2. Die clamping mechanism as claimed in claim 1 wherein the platen and ram of a press upon which the die set is to be mounted are each provided with a plurality of rows of threaded holes therein, each of the anchor bars is positioned to overlie a row of the holes and is provided with a plurality of holes therethrough located to register with selected ones of the threaded holes over which said each anchor bar is positioned, and a plurality of screws inserted one in each of a selected plurality of such holes in said each anchor bar and screwed into the threaded hole in register therewith, each of said screws being drawn down tight to secure the anchor bars firmly in position.
 3. Die clamping mechanism as claimed in claim 1 wherein each of the holes transversely through each of the anchor bars is elongated lengthwise of its respective anchor bar to provide limited adjustment of a hold down rod inserted in such hole.
 4. Die clamping means as claimed in claim 1 wherein an end portion of each hold down rod has a non-circular end portion formed thereon, and a socket wrench has a non-circular socket therein shaped to receive the non-circular end portion of the hold down rod in closely interfitted relation therein for turning each hold down rod about its axis into clamping relation with a die end flange therebeneath. 